From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sandeen Subject: [PATCH V2] filefrag: count 0 extents properly when verbose Date: Thu, 05 May 2011 13:21:08 -0500 Message-ID: <4DC2EA94.8040100@redhat.com> References: <4CEC4C86.1030806@redhat.com> <4D9F3B71.2050808@redhat.com> <569EBA4C-A6BB-4E64-88B9-F2F946891B56@dilger.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: ext4 development To: Andreas Dilger Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60060 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755626Ab1EESVL (ORCPT ); Thu, 5 May 2011 14:21:11 -0400 In-Reply-To: <569EBA4C-A6BB-4E64-88B9-F2F946891B56@dilger.ca> Sender: linux-ext4-owner@vger.kernel.org List-ID: # rm -f a; touch a; filefrag a /boot/a: 0 extents found works properly, but # rm -f a; touch a; filefrag -v a Filesystem type is: ef53 Filesystem cylinder groups is approximately 61 File size of a is 0 (0 blocks, blocksize 1024) ext logical physical expected length flags a: 1 extent found yields 1 extent when it should be 0. Fix this up by special-casing no extents returned in verbose mode; skip printing the header for the columns too, since there are no columns to print. Also, in nonverbose mode we can set fm_extent_count to 0 so that FIEMAP will just query the extent count without gathering details; clarify this with a comment. Addresses-redhat-bugzilla: 653234 Signed-off-by: Eric Sandeen diff --git a/misc/filefrag.c b/misc/filefrag.c index d604b6c..2795e15 100644 --- a/misc/filefrag.c +++ b/misc/filefrag.c @@ -180,6 +180,10 @@ static int filefrag_fiemap(int fd, int blk_shift, int *num_extents) memset(fiemap, 0, sizeof(struct fiemap)); + /* + * If count (and therefore fm_extent_count) == 0, FIEMAP + * returns count of extents found without filling in details. + */ if (!verbose) count = 0; @@ -204,6 +208,14 @@ static int filefrag_fiemap(int fd, int blk_shift, int *num_extents) } if (verbose && !fiemap_header_printed) { + /* + * No extents on first call? + * Skip header and show 0 extents. + */ + if (fiemap->fm_mapped_extents == 0) { + *num_extents = 0; + goto out; + } printf(" ext %*s %*s %*s length flags\n", logical_width, "logical", physical_width, "physical", physical_width, "expected");